HUT77288A - High purity n-(4-[n,n-bis(2-iodoethyl)amino]phenoxycarbonyl)-l-glutamic acid - Google Patents

Description

The present invention relates to high purity N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid, its hydrogen iodide salt, pharmaceutical compositions containing them and hydrogen refers to the preparation of an iodide salt.

The hydrogen iodide salt of the present invention is prepared by cleavage of the protecting groups of a compound of formula I wherein Prl and Pr2 are protected in the presence of hydrogen iodide. The hydrogen iodide salt thus obtained is a crystalline material which is very easy to purify and affords highly pure N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid. possible.

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Represented by: Dr. Jalsovszky Györgyné Lawyer Associate: Dr. Tóth-Urbán László lawyer

158/1041

HIGH PURITY N- [4- (N, N-BISZ / 2-IODO-ETHYL / -AMINO) -PHENOXYCARBONYL] -L-GLUTAMIC ACID

ZENECA LIMITED,

London, United Kingdom

inventors:

HEATON David William, Macclesfield,

DINES Susan, Macclesfield,

Robert Dowell lan, Macclesfield,

Cheshire,

Cheshire,

Cheshire,

Great Britain

The announcement

priority:

The international

International Day: 19 95. 12.

12, 1994

application number publication number

21st

23. (9426133.6) GB

PCT / GB95 / 02 997

WO 96/20169

The present invention relates to known N- [4- (N, N-bis / 2-iodoethyl / amino) -phenoxycarbonyl] -L- known for use in antibody-directed enzymatic prodrug therapy (hereinafter ADEPT). glutamic acid, a new high purity form of this

2 relates to a new salt of the compound, to pharmaceutical compositions containing them, and to the preparation of a new salt.

N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid is disclosed in WO 94/02450. International Publication. Example 33 of the cited publication describes the trifluoroacetic acid salt of the compound obtained as a gum. The known rubber-like form of the compound, due to known difficulties in the handling of rubber-like materials, could not produce a product of very high purity. Neither the hydrogen iodide salt of the compound nor the parent compound in high purity is mentioned in the literature.

According to the invention, N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid is prepared in substantially pure form.

By substantially pure designation, the product is free from impurities, including solvents, which can be contained in the synthesis, at least 95% (preferably at least 96%, more preferably at least 97%, particularly preferably at least 98%). . This very high degree of purity was achieved only by the application of the present invention by the formation of the hydrogen iodide salt of the compound (which can be obtained in crystalline form). The formation of crystalline material provides a very pure product because the crystalline salt can be well separated from the formation reaction mixture and can be easily removed by solvent washing to remove impurities (including solvents) from the synthesis. The substantially pure product is preferably marketed as a dry substance which is a buffer

- after addition of 3 it can be converted into a formulation suitable for intravenous administration.

The invention further relates to the hydrogen iodide salt of N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid. This salt is preferably substantially pure and is preferably crystalline. The crystalline material preferably has a melting point of 142-145 ° C and has an X-ray powder diffraction spectrum substantially

1 is shown.

The salt formation has the following advantages: the salt is thermally stable; the salt is easily separated from the reaction mixture, which simplifies both synthesis and purification;

improves the purity of the product and reduces the hygroscopic nature of the product and its tendency to liquefy, which makes handling easier.

While not wishing to be bound by theory, it is believed that the presence of HI in some way contributes to reversing the potential degradation of the prodrug in the range of the mustard-alkylating biosystem. If the prodrug is stored in a dry state, it may be possible to form products derived from an aziridine intermediate during storage or thermal exposure. The hydrogen iodide salt of the prodrug is surprisingly stable in aqueous solution, presumably due to the formation of iodide counter-ions. Given the therapeutic properties of sodium iodide, it would not have seemed obvious to one skilled in the art that such a high concentration of sodium iodide should be added to the prodrug for medical use (the only known use of the prodrug).

The present invention further provides a pharmaceutical composition comprising substantially pure N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid, together with pharmaceutically acceptable excipients.

The pharmaceutical composition is preferably commercially available in the form of a dry substance. The excipient is preferably a buffering agent, most preferably sodium bicarbonate. Preferably, the formulation is brought into the final dosage form shortly before use for ADEPT, preferably by the addition of a sterile diluent.

The present invention also relates to a two-component pharmaceutical composition, the first component of which comprises a dry N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid, hydrogen iodide salt, and a second component. and a sterile diluent. Preferably the salt is in the form of a crystalline material.

The present invention also relates to a process for the preparation of the hydrogen iodide salt of N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid by reacting a compound of general formula (I). The compounds of formula III wherein Prl and Pr2 represent the same or different protecting groups (preferably tert-butyl or trimethylsilyl, especially trimethylsilyl) are deprotected. The protecting groups are preferably cleaved under acidic conditions in an inert atmosphere in the presence of hydrogen iodide; the hydrogen iodide salt of N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid is formed directly. Preferably, the protecting groups are cleaved with an aprotic solvent, preferably dichloromethane or toluene, preferably in two steps, with the first step being the removal of the Prl and the toluene groups. The Pr2 protecting group is substituted with other Pr3 and Pr4 protecting groups, however, the one-step procedure in the presence of hydrogen iodide can also be used. In the two-step deprotection, the compound of formula (I) is preferably treated with trimethylsilyl iodide in the first step; thus, trimethylsilyl groups are preferably introduced as Pr3 and Pr4 protecting groups. These protecting groups are preferably removed under acidic conditions, preferably in the presence of seed crystals. In two-step deprotection, the first step usually takes 30 minutes to 24 hours at room temperature (i.e., 15-30 ° C) and the second step usually takes 1-48 hours. The reaction time for the first step is preferably from 4 to 6 hours and for the second step is preferably from 12 to 18 hours. It is essential for crystallization that the reaction mixture is stirred for a suitable period of time, preferably at room temperature, preferably below 14 hours, preferably at least 18 hours.

The present invention will be described in more detail in the following examples without limiting the scope of the invention. The complete synthesis sequence leading to the formation of the hydrochloride salt of N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid is illustrated in Scheme 1.

Example 1

Preparation of N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid, hydrogen iodide salt

25.9 g of N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid di-tert-butyl ester (5) at room temperature , under nitrogen atmosphere 173 ml • · «·

- Dissolved in 6 dichloromethane. To the solution was added trimethylsilyl iodide (26.2 mL) and the mixture was stirred for 4-6 hours. After completion of the reaction, the solution was slowly added to a mixture of diethyl ether (834 mL) and acetic acid (43 mL). Preferably, this mixture also contains seed crystals of the final product (once added to the mixture is effective throughout). The resulting slurry was stirred for 18 hours at room temperature to form a crystalline material (this lengthy stirring is essential for crystal formation). The desired end product, i.e. the N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid, hydrogen iodide salt (compound of formula (6)) is crystalline. form, washed twice with 150 ml diethyl ether and dried in a vacuum oven to constant weight. 22.1 g of product are obtained. 142-145 ° C (dec.). Optical rotation: [α] ²⁵ D = -21.1 ° (c = 1%, in dimethylformamide).

^: Η NMR _(DMSO-d6): δ 7.93 (d, 1H);

6.91 (d, 2H), 6.63 (d, 2H), 4.0 (m, 1H), 3.69 (t, 4H), 3.28 (t, 4H), 2.33 (m , 2H), 2.0 (m, 1H), 1.8 (m, 1H).

¹³ C NMR data (chemical shifts relative to DMSO / 39, β δ /): 3, 9, 52, 9, 143, 0, 112.1, 122, 6,

142.0, 154, 9, 53.2, 26, 1, 30, 1, 173, 6, 173.2.

Analytical data for C ₁₆ H ₂ O ₂ N ₂ 0 ₆ . According to the formula HI:

date: C: 26.9% H, 3.1% N: 3.8%, I: 52.4%, found: C: 26.7% H, 3.0% N: 3.9%, I: 52.9%. THE as starting material N- [4- (N, N-bis

(2-Iodoethyl-amino) -phenoxycarbonyl] -L-glutamic acid di-tert-butyl ester (Compound 5) was prepared as follows:

• ··· ·

- Step a) Preparation of N- (4-Nitrophenoxycarbonyl) -L-glutamic acid (compound of formula 1):

73.6 g of L-glutamic acid (compound b) were suspended in 750 ml of dichloromethane in a 1 liter flask. For the suspension in one installment

N, N-diisopropylethylamine (193.9 g) was added followed by trimethylsilyl chloride (135.8 g) over 20 minutes while maintaining the temperature at or below reflux temperature [unless cooling was applied the temperature of the mixture is increased from 13 ° C to 40 ° C when trimethylsilyl chloride is added]. After the addition, the mixture was refluxed for 1.5 hours and then cooled to 1 ° C. L-glutamic acid bis (trimethylsilyl ester) was obtained.

100.8 g of p-nitrophenyl chloroformate (100.8 g) were dissolved in 375 ml of dichloromethane in a clean, dry 3 L reactor and cooled to -3 ° C. To this cool solution was added L-glutamic acid bis (trimethylsilyl ester) solution as previously obtained, keeping the temperature below 10 ° C. After the solution was added, the mixture was stirred for 15 minutes and then cooled to about 5 ° C. A mixture of 750 ml of water and 148 ml of concentrated aqueous hydrochloric acid was diluted with dilute aqueous hydrochloric acid and the resulting dichloromethane solution was added over 15 minutes while maintaining the temperature at about 20 ° C.

After the addition of the solution, the mixture was stirred for 30 minutes at 20 ° C and allowed to settle for 30 minutes. The mixture was separated into three phases. The lower phase was lowered and discarded and · ^; ·· ·· ··: ·. ·:. 8 products were extracted with 1000 ml, then 500 ml of methyl isobutyl ketone. The two organic solutions were combined, washed with saturated aqueous sodium chloride solution (250 mL) and the solvent was evaporated under reduced pressure at 40 ° C bath. The resulting white solid was dissolved in ethyl acetate (600 mL) at 40 ° C, hexane (600 mL) was added and the mixture was cooled to 20 ° C with stirring and stirred overnight. The solid was filtered off. The product (126 g, 77%) was washed with ethyl acetate / hexane (1: 1, 300 mL) and dried to constant weight at 50 ° C.

¹ H NMR (DMSO-d ₆ ): δ 8.45 (d, 1H),

8.25 (d, 2H), 7.4 (d, 2H), 4.07 (m, 1H), 2.35 (m, 2H), 2.05 (m, 1H), 1.85 (m) , 1H).

Step b: Preparation of N- (4-Nitrophenoxycarbonyl) -L-glutamic acid di- (tert-butyl ester) (Compound 2)

2120 g of the compound of formula (1) obtained in step a) were charged to a 100 L reactor and 24 L of methyl isobutyl ketone was added. The resulting slurry was heated to 50 ° C, and after dissolution of the solid, the solution was cooled to 0-5 ° C and concentrated sulfuric acid (700 ml) was added over 10 minutes.

An isobutylene was condensed into a 10 L empty reaction vessel at a temperature between -25 ° C and -30 ° C and the isobutylene was added to the reaction mixture at 0-5 ° C over 18 minutes under argon. The mixture was heated to 18-20 ° C over 2 hours and then stirred at 18-20 ° C for 18 hours.

A solution of 2332 g of sodium bicarbonate in 27.1 liters of water was cooled in an ice bath to 0-5 ° C for 20 minutes.

• · · · · ί: · ♦ .:., ·,. · ··. ·

The reaction mixture was added at 9 pounds. The mixture was allowed to warm to 18-20 ° C with stirring and then allowed to stand until the phases were separated. The upper organic layer was separated and washed with 9.87 g of 0.36 M potassium dihydrogen orthophosphate buffer (530 g of potassium dihydrogen orthophosphate was dissolved in 9.87 L of water to prepare the buffer).

The organic phase was separated and evaporated on a rotary evaporator. 2334 g of an amber oily residue containing the desired product were obtained.

^: Η NMR _(DMSO-d6): 5 7.33 (d, 2H);

8.24 (d, 2H), 5.90 (d, 1H), 4.32 (m, 1H), 2.0-2.4 (m, 4H),

1.50 (s, 9H), 1.46 (s, 9H).

Step c) Preparation of N- (4-Aminophenoxycarbonyl) -L-glutamic acid di- (tert-butyl ester) (Compound 3)

A well-equipped hydrogenation vessel was charged with 10% palladium on charcoal catalyst (200 g aqueous wet pulp) and 1.0 kg of a solution of compound 2 in 5 liters of n-butyl acetate was added. The slurry was cooled to 15 ° C with stirring, and the temperature was hydrogenated by external cooling at 15-25 ° C under a slight excess of hydrogen (0.1 bar) (hydrogenation exothermic). After uptake of hydrogen, the catalyst was filtered off and washed with n-butyl acetate (2 x 500 mL). The filtrates were combined and washed with dilute aqueous sodium hydroxide solution (0.114 liters of 1.5 g / ml aqueous solution of sodium hydroxide 46-48% w / v to 2 liters of water) and twice with 2 liters of water. The organic phase (about 7 liters) was concentrated under reduced pressure at 35-45 ° C to a final volume of about 2 liters. This solution * · · * ··

-10 ° C with 5 liters of Essochem Solvent 30 ^1R) [hydrocarbon solvent, Exxon Chemical Ltd. (POBox 122, 4600 ^)] , heated to 50-55 ° C with stirring.

Parkway, Fareham, Hampshire PO15, 7AP, UK)] (hexane may be used instead). The mixture was cooled to + 5 ° C and the precipitated solid was filtered off. The solid was washed twice with a mixture of 250 ml of n-butyl acetate and 750 ml of Essochem Solvent, aspirated to dryness and dried under reduced pressure at room temperature. 0.54 kg of the desired product is obtained.

¹ H NMR (DMSO-d ₆ ): δ 7.80 (d, 1H),

6.45-6, 75 (m, 4H), 7.95 (broad s, 2H), 3.95 (m, 1H), 2.4 (m,

2H), 1.7-2.0 (m, 2H), 1.4 (18H).

Mass Spectrum (MH +): 395.

Step d: N- [4- (N, N-Bis (2-Hydroxyethyl) amino) phenoxycarbonyl] -L-glutamic acid di-tert-butyl ester [Compound 4 ]:

g of compound (3) obtained in step c) was dissolved in a mixture of 430 ml of acetic acid and 430 ml of water. To the resulting cloudy solution was added 78 g of ethylene oxide gas with stirring over several hours while maintaining the temperature below 30 ° C. Any excess gas was trapped in a solid-carbon cooled trap. After stirring for at least 18 hours, the mixture was sampled and assayed by TLC to complete the reaction. After completion of the reaction, the mixture was evaporated to dryness in a cold-finger Buchi Rotovapor under reduced pressure. The oily residue was dissolved in 600 ml of ethyl acetate and the solution was dissolved in 25 g of sodium bicarbonate in 350 ml of water ··· ·

-11. The organic layer was separated, washed with water (2 x 250 mL), dried over magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure. 77 g of an oily substance were obtained, containing about 50% by weight of the desired product.

The desired product was crystallized as follows: 57 g of 82% pure product was dissolved in ethyl acetate (228 ml) at 40 ° C, cooled to 22 ° C, and 5.7 g of Darko KB purifying charcoal [Norit UK Ltd.]. company (Clydesmill Market,

Cambuslang Industrial Estate, Glasgow G32 8RF) was added. The mixture was stirred for 90 minutes then filtered through celite and the filter cake washed with ethyl acetate (57 mL). The resulting solution was heated to 50 ° C and 570 ml of hexane fraction was added at 45-50 ° C over 45 minutes. After the addition, the solution was allowed to cool spontaneously, seed crystals were added at 35 ° C and stirred overnight. The mixture was heated at 15 ° C for 1 hour and then filtered. The solid was filtered, washed with 2: 1 hexane / ethyl acetate (45 mL) followed by hexane (45 mL) and then dried at 50 ° C. 35.7 g of product are obtained; yield: 76%. M.p. 91-93 ° C.

¹ H NMR (DMSO-d ₆ ): δ 6.85 (d, 2H),

6.6 (d, 2H), 4.65 (m, 1H).

Step e) N- [4- (N, N-Bis (2-Iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid di- (tert-butyl ester) [Compound 5 ]:

32.6 g of triphenylphosphine are dissolved in 200 ml of dichloromethane under nitrogen, 8.4 g of imidazole are added, and after the solid is completely dissolved, the solution is cooled to 5 ° C. 31.5 g of iodine was added in portions while maintaining the temperature below 21 ° C. After the addition of iodine, the reaction mixture was allowed to warm to room temperature over 1 hour. Then, while maintaining the temperature below 26 ° C, a solution of the product of step d) in dichloromethane (50 ml) was added and the resulting mixture was stirred overnight until the reaction was complete. The mixture was cooled to 5 ° C and 120 ml of 10% potassium iodide solution was added keeping the temperature below 10 ° C. After settling for about 10 minutes, the lower organic layer was separated, the solvent was evaporated and the oily residue was dissolved in 100 ml of ethyl acetate. Cyclohexane (200 mL) was added slowly to precipitate triphenylphosphine oxide. After stirring for at least 10 minutes, the solid was filtered off and washed with 60 mL of 2: 1 cyclohexane / ethyl acetate. The filtrate was evaporated and the residue was triturated with methyl tert-butyl ether (200 mL). The resulting suspension was passed through a column packed with 100 g of silica gel, the column was washed with methyl tert-butyl ether (2 x 100 ml), and the combined organic liquids were evaporated. 26.0 g of the expected product are obtained in the form of a colorless oil.

¹ H NMR (CDCl ₃ ) δ 7.0 (d, 2H), 6.6 (d, 2H), 5.4 (d, 1H), 4.3 (m, 1H), 3.7 (t, 4H), 3.2 (t, 4H),

2.4-1.9 (m, 4H), 1.5 (s, 9H), 1.45 (s, 9H).

Example 2

Medical preparation

Pack sizes of 3 vials of type 1 20 ml containing 610 mg prodrugs, 3 vials of 11 ml of 2.15% w / v sodium hydrogen carbonate solution (for final dosing). form), 3 18G needles and a hydrophobic filter (to open the vials) and 3 disposable sterile 0.22 micron filters (for aqueous solutions). Store in a refrigerator (2 ° C - 8 ° C).

The formulation is used for therapeutic treatment (the operations to be enumerated are preferably carried out under sterile conditions). At least one hour prior to administration, open one ampoule of prodrug using a needle and a hydrophobic filter. 10 ml of sterile aqueous sodium bicarbonate solution (2.15% w / v) were introduced into the vial via the stopper using a syringe and needle. Leaving the opening in place, shake the vial gently until a clear solution is formed. The resulting solution contains 50 mg / ml prodrug (calculated as free base). The solution to be injected is then aspirated through a sterile filter into a sterile syringe. Insert a sterile injection needle with a stopper on the filter, and store the syringe in a cold place until the solution is administered. It is prepared in the same way for administration

The contents of the other ampoules at 1-1 hour intervals; three dose units are administered at 1-1 hour intervals. It is noted that this composition is suitable for use with an ADEPT antibody-enzyme conjugate such as WO 94/02450. International Publication No. 5405 990; A5B7 antibody carboxypeptidase G2 conjugate.

-143. example

Examination of antitumor activity

The antitumor activity of the hydrogen iodide salt of N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid (prodrug) was investigated in the following model:

10 ⁷ LoVo tumor cells (ECACC 87060101) were injected subcutaneously in the hips of thymic-deficient mice. When the tumor grafts reached a diameter of 4-5 mm, the mice received 2.5 mg / kg (500 units of CPG2 activity / kg) intravenously.

F (ab ') ₂ A5B7-CPG2 Conjugate (see WO 94/02450 and US 5,405,990). After a 72 hour pause (during which the conjugate is cleared from the blood and normal tissues and localized in the tumor), the animals were given three separate intraperitoneal doses of 70 mg / kg three times for a total of 2 hours at 1-1 hour intervals. Combination of conjugate and prodrug resulted in tumor regression and delayed tumor growth for more than 30 days. Only a slight change in body weight and peripheral white blood cell count was observed with the above conjugate / prodrug combination. In the above model, a significant antitumor effect was observed when 0.25-10 mg / kg conjugate was combined with three times 50-90 mg / kg prodrug. When the prodrug was administered in three separate doses over 2 hours, a greater antitumor effect was observed than when the prodrug was administered in a single dose.

Based on the above data, the clinical dose of conjugate may be 0.025-1.0 mg / kg, preferably 0.5-1.0 mg / kg. The prodrug should be administered after the conjugate has been localized in the tumor and cleared from blood and normal tissues (less than 1 µg / ml of conjugate in plasma). Clinical studies with AF (ab ') ₂ A5B7-CPG2 conjugate (Bagshawe, Clinical Pharmacokinetic Concepts 27, 368 (1994)) indicate this condition after administration of the conjugate.

It is set after 48-96 hours. The prodrug is preferably administered over 2 hours, at intervals of 1-1 hour, in 3 intravenous doses. Based on tumor size in mice, the prodrug is expected to exert its antitumor activity at a total dose of 15-150 mg / kg, however, it is obvious that standard prodrug / dose studies should be performed with the prodrug to determine the optimal therapeutic dose.

Example 4

X-ray powder diffraction pattern

For X-ray powder diffraction Siemens (R)

A D5000 diffractometer was used. Approximately 1 g of the crystalline N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid hydrochloride salt to be examined was sampled (desired fine particle size). the sample was gently rubbed in a mortar if necessary), the sample was carefully and live filled into a standard Siemens sample holder and leveled with a standard glass microscope slide. The sample was rotated at 30 rpm (this improves the counting statistics) and irradiated with X-rays of 1.5406 Angstroms generated by a long-fine copper tube operated at 40 kV, 40 mA. Passing the parallelized X-rays through an automatically adjustable di-16-slit slit set to V20, maintained constant illumination over the entire scanning range terület - Θ, and reflected radiation through a 2 mm anti-slip gap and a 0.2 mm detector slit. Each sample was scanned at 4 seconds / 0.02 ° at 2Θ intervals between 2 ° and 45 ° 2Θ (continuous scan); Thus, the diffraction pattern of each sample took 2 hours, 23 minutes and 20 seconds. The scintillation counter mounted on the instrument was used as a detector. For control and data acquisition purposes, we used a Dell 325P ^(R1 personal computer) powered by a Diffrac AT ^(R> (Sobacim) program developed specifically for this purpose. The crystalline N- [4- (N, N-bis / 2-iodoethyl / amino) The x-ray powder diffraction pattern of the phenoxycarbonyl] -L-glutamic acid, hydrogen iodide salt, as shown above, is shown in Figure 1.

Claims (16)

Patent claims 1. Substantially pure N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid. 2. N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid, which is at least 95% free of impurities that may be obtained during synthesis. 3. N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid, hydrogen iodide salt. Hydrogen iodide salt according to claim 3, characterized in that it is a substantially pure substance. 5. Hydrogen iodide salt according to any one of claims 1 to 3, characterized in that it is a crystalline material. Hydrogen iodide salt according to claim 5, characterized in that it is a crystalline material having a melting point of 142-145 ° C. 7. Hydrogen iodide salt according to any one of claims 1 to 4, characterized in that its X-ray powder diffraction pattern is substantially as shown in Figure 1. 8. A pharmaceutical composition comprising substantially pure N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid and pharmaceutically acceptable excipient (s). contain. The pharmaceutical composition of claim 8, wherein the composition is a dry substance. Pharmaceutical composition according to claim 9, characterized in that it contains a buffering agent -18 ·· < ¹ · • · 1 • · · Pharmaceutical composition according to claim 10, characterized in that it contains sodium bicarbonate as a buffering agent. 12. A two-component medical kit, characterized in that the first component is the compound of claims 9-11. A pharmaceutical composition according to any one of claims 1 to 6, and a second component comprising a sterile diluent for the administration of the first component to the dosage form. 13. A process for the preparation of the hydrochloride salt of N- [4- (N, N-bis (2-iodoethyl) amino) phenoxycarbonyl] -L-glutamic acid, characterized in that a salt of the formula (I) The compounds of formula II wherein Pr1 and Pr2 are the same or different protecting groups are deprotected in the presence of hydrogen iodide. 14. A process according to claim 13 wherein Prl and Pr2 are a t-butyl group of formula (I). 15. The process of claim 13, wherein the deprotection is carried out in two steps, the first step of which is to replace the tert-butyl groups of Pr1 and Pr2 with trimethylsilyl groups, and the latter protecting groups are hydrogen iodide. in its presence. 16. We are characterized in that 13 is a group. The process of claim 1 wherein Prl and Pr2 are trimethylsilyl compounds of formula (I). Jalsovezk lawyer 1093 Budapest. Tel .: 218-4146 iiW PUBLISHING PAPER • · Dr. Jalsovt 1093 Budi Tel .: 21 yörgyné u. 24. # 18-4506 I PUBLICATION LITERATURE 3/2 CO CO Et-N (i-propyl) ₂ , trimethylsilyl chloride, ethyl acetate, isobutylene / H ₂ SO ₄ H ₂ , Pd / C CM D TJ O = = Φ - -CO 4- » N · «Ό co ®. = E> P, 1 {ü ~ ο θ f— Ό UJ LU S SS o N CO T3 CL CO £ Q_ > ro V) sS the) 0 Ό φ CO the? Φ E N '> xf 'x 0 1 c <L) NEW JRO N '<Ü> Ό Ό ra ω 1093 Budi